66 PACIFIC COAST AVIFAUNA No. 12 



Birds West. U. S., 2d ed., 1904, p. 260. (15) Grinnell, Condor, vii, 1905, p. 50. {16) 

 C(hilds), Warbler, ii, 1906, p. 33. (17) Grinnell, Condor, viii, 1906, p. 74. (18) 

 Mearns, Bull. U. S. Nat. Mus., lvi, 1907, p. 141. (19) A. O. U. Committee, Auk, xxv, 

 1908, p. 353. 



E[mpiclonax'\. insulicola (20) Coues, Key N. Am. Birds, 5th ed., 1903, p. 531. 



Empidonax difficilis difficilis (21) Ridgway, Birds North & Mid. Am., iv, 1907, p. 578. 

 (22) Willett, Fac. Coast Avif., 7, 1912, p. 64. (23) Wright and Snyder, Condor, xv, 

 1913, p. 91. (2^) Grinnell, Pac. Coast Avif., 11, 1915, p. 91. 



Common in summer on the larger islands. The subspecies insulicola was 

 described by H. C. Oberholser (8) from a specimen taken on Santa Rosa Island, 

 July 3, 1892. From difficilis it was said to differ in being darker, browner 

 above, especially the head, and paler below, especially anteriorly. There is a 

 great deal of individual and seasonal variation in birds from the mainland, and 

 upon bringing large series together since that time, other writers have claimed 

 that the insular bird was not entitled to subspecific rank, wherefore it was sub- 

 sequently rejected by the A. 0. U. Committee (19). 



C. B. Linton (5) states that the earliest birds he saw on Clemente were a 

 pair on April 1, 1907, and that but three or four were noted as late as October. 

 They are quite numerous on Catalina and mostly frequent the shady dark parts 

 of the canyons. A. van Rossem and I found the species to be not particularly 

 numerous and rather shy on Santa Cruz in April, 1911. Linton (ff) saw and 

 heard several there throughout November and as late as December 15, 1907. 



A variety of situations are used as nesting sites, the favorite being in an ir- 

 regularity of a cliff or large boulder; but the fork of a small tree, a niche in a 

 large trunk, or the wall of a sea cave is often chosen. Two broods are raised each 

 season. I have found uncompleted nests after the middle of April, and "Black*' 

 (E. W. Blake) (10) has noted a pair building as late as July 10, 1886. 



116. Empidonax trailli trailli (Audubon) 



Traill Flycatcher 



Empidonax traillii (1) Osburn, Condor, xi, 1909, p. 137. 



C. C. Lamb (MS) shot one of these birds on the south island of the Corona- 

 dos group April 4, 1908. 



117. Empidonax hammondi (Xantus) 



Hammond Flycatcher 



Empidonax hammondi ? (1) Cooper, Proc. Calif. Acad. Sci., iv, 1870, p. 77. 



L. M. Iluey {MS) shot a single specimen on San Clemente Island, April 9, 

 1915. Also reported conditionally by J. G. Cooper (i) from Catalina and Santa 

 Barbara islands. However, as the latter failed to report difficilis in the same 

 paper, it is quite possible that the birds which he saw were referable to the lat- 

 ter species. 



